The issue of sharks attacking underwater cables dates back decades. In 1989 the New York Timesreported instances of sharks showing an “inexplicable taste” for the then-new fiber optic cables that lay between the U.S. and Europe.

Last week at a Google Cloud Roadshow event in Boston Dan Belcher, a product manager on the Google cloud team in an opening keynote said that Google goes to great lengths to protect its infrastructure, including wrapping its trans-Pacific underwater cables in Kevlar to prevent against shark attacks, he said. Google did not respond to a request for additional information.

This primer about Google’s fiber cables explains the makeup of the company’s transmission lines. Fiber cables use lasers to send information through glass, which allows the cables to support transmission speeds of up to 1 gigabit per second, about 100 times faster than the average copper cable connection.

Google

Google's fiber cables are made of glass and have a Kevlar-like protective material on the outside.

“Since fiber is made of fragile glass, its casing is built to protect it from breaking. A fiber-optic cable often includes (listed from the outer layer inward): An outer polyurethane jacket, a protective layer (made from a material like kevlar), a plastic coating (in different colors, so technicians can follow the path of each strand), and enclosed in all of these, a glass fiber.”

Note that the official Google presser says the company uses a Kevlar-like material, not Kevlar, which is a registered product.

Why are sharks attracted to fiber cables? The website oAfrica, which tracks digital news on the continent, theorized in 2009 that perhaps the emission of electricity from the fiber cables may attract the sharks, who mistake the currents for prey.

“Unlike short-haul terrestrial fiber cables or old copper cables where the fiber did not emit noticeable fields, undersea cables must carry high voltage power to the undersea repeaters, which result in both electric and magnetic fields around and along the cable … Some sharks mistaken the electric fields for distressed fish and attempt to feed on the cable.”

Whether sharks are still biting cables or not, Google’s ready for them.

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Senior Editor Brandon Butler covers the cloud computing industry for Network World by focusing on the advancements of major players in the industry, tracking end user deployments and keeping tabs on the hottest new startups.